Timing in javascript vs real time

Question

I have a question: When I do a countdown in JavaScript, and I have a function of the form:

        <script>
var interval;
var minutes = 1;
var seconds = 5;
window.onload = function() {
    countdown('countdown');
}

function countdown(element) {
    interval = setInterval(function() {
        var el = document.getElementById(element);
        if(seconds == 0) {
            if(minutes == 0) {
                el.innerHTML = "countdown's over!";                    
                clearInterval(interval);
                return;
            } else {
                minutes--;
                seconds = 60;
            }
        }
        if(minutes > 0) {
            var minute_text = minutes + (minutes > 1 ? ' minutes' : ' minute');
        } else {
            var minute_text = '';
        }
        var second_text = seconds > 1 ? 'seconds' : 'second';
        el.innerHTML = minute_text + ' ' + seconds + ' ' + second_text + ' remaining';
        seconds--;
    }, 1000);
}
</script>

The time between each one performance of the function is exactly 1 sec. or there is some delay caused by time due to perform body of function?

`countdown` is not a core JS function. Is this from some library? — Dancrumb, Dec 20 '12 at 17:55
It seems like you left a line out. Perhaps you were trying to call `setInterval`? — benekastah, Dec 20 '12 at 17:57
You're code is a function that does nothing. Was there a timer created in there that you cut out? — dqhendricks, Dec 20 '12 at 17:58

score 1 · Accepted Answer · edited May 23 '17 at 11:56

1

No, setTimeout() and setInterval() have impredictable accuracy, as said in this other question you can get better precision by setting a timeout once and than using (new Date()).milliseconds to do time related actions instead of using setTimeout() for every thing

edited May 23 '17 at 11:56

Community

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1

answered Dec 20 '12 at 18:02

Polyana Fontes

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score 0 · Answer 2 · answered Dec 20 '12 at 18:01

0

There are functions setTimeout(fnc, delay) and setTimeout(fnc, delay) that are said to call fnc after at least delay ms. See MDN for details.

answered Dec 20 '12 at 18:01

Artem Sobolev

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Timing in javascript vs real time

2 Answers2